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The deep ice-sheet coring (DISC) drill was used for production ice-core drilling at WAIS Divide in Antarctica for six field seasons between 2007 and 2013. Continuous ice-core samples were obtained between the snow surface and 3405 m depth. During the 2012/13 austral summer, the DISC drill’s newly designed replicate ice-coring system was utilized to collect nearly 285m of additional high-quality core samples at depths of high scientific interest. Annual progress graphs are described, as well as milestones achieved over the course of the project. Drilling operations, challenges encountered, drill fluid usage, drilling results, and the drill crew’s experiences with the DISC drill and replicate coring system during production drilling are described and discussed in detail. Core-processing operations are described briefly, as well as the logistical undertaking of the DISC drill’s deployment to Antarctica.

Drilling the WDC06A borehole at the West Antarctic Ice Sheet (WAIS) Divide with the Deep Ice Sheet Coring (DISC) drill began in December 2007 and was successfully completed in December 2011 to a depth of 3405 m. The design and construction of a replicate coring system for use with the existing DISC drill began in 2010. In January 2012, the new replicate coring system was tested in the parent borehole at WAIS Divide. While a full deviation was not completed during the test period, much was learned about the mechanical, electrical and operational aspects of the system. Extensive testing and modifications were done over the northern/boreal summer to prepare the system for the upcoming and final season of the project. Further tuning of the system continued during the 2012/13 field season at WAIS Divide. This paper identifies the issues found with the system during the initial test season and discusses solutions, methods and testing done to arrive at an operational system.

The drilling of a deep borehole in ice is an undertaking that spans several seasons. Over recent decades such drilling has become widespread in both polar regions. Owing to the remoteness of the drill sites, considerable cost is associated with the drilling of a deep borehole of several thousand meters. The replicate coring system allows re-drilling of ice core at select depths within an existing parent borehole. This effectively increases the yield of the existing borehole and permits re-sampling of ice in areas of high scientific value. The replicate coring system achieves this through the combination of actuators, motors, sensors and a computerized control system. The replicate coring drill is a further development of the deep ice-sheet coring (DISC) drill, extending the capabilities of the DISC drill to include replicate coring.

The replicate ice-coring system was developed by Ice Drilling Design and Operations (IDDO) for the US National Science Foundation. The design of the system leverages the existing infrastructure of the deep ice-sheet coring (DISC) drill to create a steerable drill capable of recovering replicate core at any targeted depth in an existing borehole. Critical requirements of the system include: collecting up to 400 m of core from the high side of an open hole; maintaining access to the entire borehole for logging tools; collecting up to four cores at a single depth; and operating to a depth of 4000m at −55°C and 34 MPa. The system was developed and tested from 2010 through 2012 and integrates several new mechanical subsystems, including two electromechanical actuators capable of pushing the sonde to any targeted azimuth, new reduced diameter core and screen barrels made from off-the-shelf casing tube, and new cutter heads optimized for the multiple stages of the replicate coring procedure. The system was successfully deployed at West Antarctic Ice Sheet (WAIS) Divide in the 2012/13 field season, recovering 285 m of core from five intentional deviations at four target depths.

To detail the activities of the Veterans Health Administration (VHA) Antimicrobial Stewardship Initiative and evaluate outcomes of the program.

DESIGN

Observational analysis.

SETTING

The VHA is a large integrated healthcare system serving approximately 6 million individuals annually at more than 140 medical facilities.

METHODS

Utilization of nationally developed resources, proportional distribution of antibiotics, changes in stewardship practices and patient safety measures were reported. In addition, inpatient antimicrobial use was evaluated before and after implementation of national stewardship activities.

RESULTS

Nationally developed stewardship resources were well utilized, and many stewardship practices significantly increased, including development of written stewardship policies at 92% of facilities by 2015 (P<.05). While the proportional distribution of antibiotics did not change, inpatient antibiotic use significantly decreased after VHA Antimicrobial Stewardship Initiative activities began (P<.0001). A 12% decrease in antibiotic use was noted overall. The VHA has also noted significantly declining use of antimicrobials prescribed for resistant Gram-negative organisms, including carbapenems, as well as declining hospital readmission and mortality rates. Concurrently, the VHA reported decreasing rates of Clostridium difficile infection.

CONCLUSIONS

The VHA National Antimicrobial Stewardship Initiative includes continuing education, disease-specific guidelines, and development of example policies in addition to other highly utilized resources. While no specific ideal level of antimicrobial utilization has been established, the VHA has shown that improving antimicrobial usage in a large healthcare system may be achieved through national guidance and resources with local implementation of antimicrobial stewardship programs.

This paper describes strategies to search for, detect, and identify organic material on the surface and subsurface of Mars. The strategies described include those applied by landed missions in the past and those that will be applied in the future. The value and role of ESA's ExoMars rover and of her key science instrument Mars Organic Molecule Analyzer (MOMA) are critically assessed.

Prelimary results of an extended program of coordinated X-ray and optical observations of TT Ari are presented. The object was observed on August 21/22 1985 both in X-rays (EXOSAT) and optical range, about 100 days after the return to the active state. The first detailed simultaneous study of TT Ari in active state indicates the presence of strongly absorbing structure in the system.

We present preliminary results of the EXOSAT X-ray observations and quasisimultaneous and simultaneous optical photometry of the X-ray source EX0020528+1454.8 = 1E0205+149 found independently as an serendipitous source both with Einstein and EXOSAT satellites. The optical counterpart is a pair of dMe stars, Our results indicate that the object is variable both in X-rays and optical wavelenghts, and probably belongs to dMe flare stars.

A comprehensive understanding of the transport properties of interfaces in high-Tc cuprates been obtained by considering their microstructure, the possibility of bending of the electronic
band structure in these materials, and the predominant dx2-y2 -symmetry of the order parameter in most high-Tc cuprates. These factors are of central importance for the critical current density and the normal state resistivity of grain boundaries and their dependencies on boundary misorientation and on applied magnetic and electrical fields. In addition, some of these factors play an important role for the transport properties of other interfaces involving high-Tc superconductors, such as superconductors-normal metal contacts.

Based on the improved understanding of the mechanisms controlling interface transport properties, we have been able to meet a long-standing challenge in high-Tc superconductivity and have increased the critical current densities of grain boundaries by large factors, using appropriate doping.

A study of Si-doped and Mg-doped AlxGa1-xN up to × ∼ 50 % and the characteristics of ultraviolet (UV) light emitting diodes (LEDs) with emission wavelengths at 340 nm and 290 nm are reported. By using grading super-lattices (SLs) before n-type AlGaN growth, surface roughness is much improved. Resistivity of 2.9×10-2 Ωcm and free electron concentrations of 2.9×10 cm- are achieved for n-type Al0.45Ga0.55N. The viability of effective p-type doping is defined by a minimum concentration of Mg required to offset the background impurities and, more importantly, a maximum limit above which inversion domains and structural defects start to nucleate, accompanied by a rapid degradation of electrical transport. Resistivity of 10 Ωcm and free hole concentrations above 1017 cm−3 are achieved for AlxGa1-xN up to × ∼ 50 % within an optimum window of Mg incorporation. Output powers up to 1.5 mW from small area 340 nm LEDs (< 100 μm diameter) and 110 μW from 290 nm LEDs (100 μm diameter) directly off a planar chip have been achieved under DC condition. For large area encapsulated lamp (1×1 mm2 device area and 0.52 mm2 mesa area), output power of 79 mW from 340 nm LEDs and 8.5 mW from 290 nm LEDs are achieved under pulse mode (1kHz, 2% duty factor).

It is still uncertain if cardiac natriuretic peptides are useful biomarkers in paediatric cardiology. In this review we identify four clinical scenarios in paediatric cardiology, where clinical decision-making can be difficult, and where we feel the paediatric cardiologists need additional diagnostic tools. Natriuretic peptide measurements could be that extra tool. We discuss and suggest N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide reference intervals for children without cardiovascular disease and cut-off points for the four specific paediatric heart conditions. We conclude that in premature neonates with persistent arterial ducts; in teenagers with tetralogy of Fallot and pulmonary regurgitation; and in children with heart transplants and potential allograft rejection cardiac peptides can provide the clinician with additional information, but in children with atrial septal defects the peptides are not helpful in guiding treatment or follow-up.

Clinical manifestations of lactase (LCT) deficiency include intestinal and extra-intestinal symptoms. Lactose hydrogen breath test (H2-BT) is considered the gold standard to evaluate LCT deficiency (LD). Recently, the single-nucleotide polymorphism C/T− 13 910 has been associated with LD. The objectives of the present study were to evaluate the agreement between genetic testing of LCT C/T− 13 910 and lactose H2-BT, and the diagnostic value of extended symptom assessment. Of the 201 patients included in the study, 194 (139 females; mean age 38, range 17–79 years, and 55 males, mean age 38, range 18–68 years) patients with clinical suspicion of LD underwent a 3–4 h H2-BT and genetic testing for LCT C/T− 13 910. Patients rated five intestinal and four extra-intestinal symptoms during the H2-BT and then at home for the following 48 h. Declaring H2-BT as the gold standard, the CC− 13 910 genotype had a sensitivity of 97 % and a specificity of 95 % with a κ of 0·9 in diagnosing LCT deficiency. Patients with LD had more intense intestinal symptoms 4 h following the lactose challenge included in the H2-BT. We found no difference in the intensity of extra-intestinal symptoms between patients with and without LD. Symptom assessment yielded differences for intestinal symptoms abdominal pain, bloating, borborygmi and diarrhoea between 120 min and 4 h after oral lactose challenge. Extra-intestinal symptoms (dizziness, headache and myalgia) and extension of symptom assessment up to 48 h did not consistently show different results. In conclusion, genetic testing has an excellent agreement with the standard lactose H2-BT, and it may replace breath testing for the diagnosis of LD. Extended symptom scores and assessment of extra-intestinal symptoms have limited diagnostic value in the evaluation of LD.

Summary

ABSTRACT

The surface and aeolian dust on Mars is rich in iron compounds, and significant quantities of dust have been observed to stick to permanent magnets that are either exposed to the dusty atmosphere, exposed to dust released by grinding into rocks, or inserted into the soil. All successful lander missions to Mars so far have carried permanent magnets of various designs for the purpose of studying dust magnetic properties. The magnetism of the aeolian dust is the result of the presence of magnetite, which apparently derives from mechanical weathering of magnetite-rich surface rocks. A strong correlation between the elements titanium and iron is observed in elemental abundance spectra of dust attracted to permanent-magnet surfaces, suggesting that the magnetite responsible for the magnetization of the dust is actually titanomagnetite. Overall, the dust can be shown to have a saturation magnetization of less than 2 A m2 kg− 1. However, some grains are significantly more magnetic, and by interaction with a permanent magnet it is possible to separate the airborne dust into populations of more and less magnetic grains. Subpopulations attracted to a magnet have been seen to have magnetizations above 7 A m2 kg− 1. The widespread presence of magnetite and other easily oxidized minerals like olivine in rocks and in the global Martian dust imply that the Martian surface has been largely devoid of liquid water for a very long time.

Background. The clinician-administered version of the Liebowitz Social Anxiety Scale (LSAS-CA) is a commonly used assessment device for the evaluation of social anxiety disorder and has been shown to have strong psychometric characteristics. Because of its apparently straightforward rating format and potential savings in time and effort, interest in the use of the LSAS as a self-report (LSAS-SR) measure has increased, and the LSAS-SR has been used in a number of studies. However, the psychometric properties of the LSAS-SR have not been well established.

Methods. This study examined the psychometric properties of the LSAS-SR in comparison to the LSAS-CA in a sample of 99 individuals with a primary diagnosis of social anxiety disorder and 53 individuals with no current psychiatric disorder.

Results. There was little difference between the two versions of the LSAS on any scale or subscale score. Both forms were internally consistent and the subscale intercorrelations for the two forms were essentially identical. Correlations of each LSAS-SR index with its LSAS-CA counterpart were all highly significant. Finally, the convergent and discriminant validity of the two forms of the LSAS was shown to be strong.

Conclusion. Results of this study suggest that the self-report version of the LSAS compares well to the clinician-administered version and may be validly employed in the assessment of social anxiety disorder.

Using production scale AIXTRON MOCVD systems various heterointerfaces in the GaInN/GaN system have been studied in depth. GaInN single hetero layers were investigated to optimise photoluminescence properties. Several approaches of capping GaInN/GaN with another GaN layer to develop high quality double-hetero (DH) structures were presented. Using an optimised interfacing technique we obtain device quality DH structures with state of the art composition uniformity across a 2 inch wafer